This invention relates generally to metallic components and more particularly for a method of producing fatigue-resistant and damage-tolerant metallic components.
Various metallic components, such as gas turbine engine fan and compressor blades, are susceptible to cracking from fatigue and damage (e.g. from foreign object impacts). This damage reduces the life of the part, requiring repair or replacement.
It is known to protect components from crack propagation by inducing residual compressive stresses therein. Methods of imparting this stress include shot peening, laser shock peening (LSP), pinch peening, and low plasticity burnishing (LPB). These methods are typically employed by applying a “patch” of residual compressive stresses over an area to be protected from crack propagation, for example a leading edge of a gas turbine engine compressor blade. However, this process is relatively slow and expensive. This procedure also modifies areas of the blade in which the aerodynamic performance is quite sensitive to dimensional variations.
Accordingly, there is a need for a method of protecting metallic components from crack propagation without altering the performance characteristics thereof.